


2+1=3

by Omness



Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: F/M, Fluff, Getting Together, M/M, Other, alternate universe where the stone event doesn't happen, senku might be a bit OOC but idk how to fix it, which i guess is Modern AU?
Language: English
Status: Completed
Published: 2021-01-17
Updated: 2021-01-17
Packaged: 2021-03-15 20:09:08
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,277
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28819041
Author URL: https://archiveofourown.org/users/Omness/pseuds/Omness
Summary: Yuzuriha and Taiju are determined to date Senku. The only problem? They don't know if Senku likes them like that. But with the help of a way too roundabout plan, they should surely find their answer.
Relationships: Ishigami Senkuu/Ogawa Yuzuriha/Ooki Taiju
Comments: 2
Kudos: 41





	2+1=3

**Author's Note:**

> The start of season two reminded me I had this fic sitting around unfinished from a year ago. So I finished it up and here it is. Hope you enjoy!

Yuzuriha and Taiju laid on the banks of the river, heads resting against their backpacks as they identified shapes in the clouds and chatted about everything and nothing.

“Hey Taiju?” Yuzuriha asked during a lull in conversation, idly running her fingers through the grass at her sides.

“Yeah Yuzuriha?” Taiju responded.

“So I know you have feelings for me-” Taiju bolted upright into a sitting position, sputtering incoherent words, Yuzuriha ignored it and continued on, “And I have feelings for you...”

Taiju slammed his hands down next to Yuzuriha, his eyes wide in shock, “How do?! You do?! Whaaat?!”

At this point Yuzuriha sat up herself, smiling fondly at Taiju, as she placed a finger against his lips, “Hush a moment would you? We’ll talk, but I want to figure something out first. Will you answer my next question completely honestly?”

Taiju went cross-eyed trying to stare at Yuzuriha’s finger, and nodded.

“Good.” Yuzuriha retracted her finger and crossed her arms, putting on as serious a thinking face as she could muster, one that Taiju found absolutely adorable, “What are your feelings toward Senku?”

“Senku?” Taiju’s voice went high and he laughed nervously. He rubbed the back of his head, knee bouncing and eyes looking everywhere but at Yuzuriha, “W-why do you ask?”

Yuzuriha grabbed both sides of Taiju’s face, trying to get him to look at her, “You said you’d be honest,”

Taiju deflated as he answered, “I uh, I may have feelings for him too,” Then he bolted upright, staring determined as he shouted, “But I fell for you first Yuzuriha! So I can always hold you first in my heart!”

Yuzuriha blushed for a moment before she said, “That’s okay, you don’t have to. Because…” she trailed off, then hid her face in her hands and mumbled.

“What was that? Taiju asked, leaning in closer.

Moving her hands enough to be heard better, Yuzuriha said, “It’s embarrassing to admit, but I also have feelings for him. I like you both.”

“Oh wow!” Taiju laughed boisterously, “Who would’ve thought! Us liking each other and Senku!”

Yuzuriya lowered her hands, smiling in relief at Taiju’s enthusiasm, “Yeah. I was actually curious because while I absolutely do want to date you. I was thinking maybe we could date Senku too? Only if you’re okay with it!” Yuzuriha exclaimed, curling her fingers tightly into the fabric of her skirt.

“Date Senku too… huh.” Taiju propped his chin in his fist, surprisingly still as he thought.

And there was quiet.

And more quiet.

Yuzuriha started to get nervous. She rocked forward as she said, “We don’t-”

“Yeah!” Taiju yelled, standing upright and startling Yuzuriha backward into the grass, “I’d wanna date you and Senku!”

Yuzuriha smiled ruefully, rubbing her head as she sat back up, “So we’re agreed then?”

“Yeah!” Taiju said, holding out a hand to help Yuzuriha up. Once she was up Taiju frowned as a thought crossed his mind, “But how does Senku feel about us?”

Yuzuriha’s eyes widened, “Oh, hmm,” she tilted her head to the side, “I don’t know. I’ve never seen him have a crush before to compare his behavior to, have you?”

Putting his chin in his fist Taiju said, “There was that one girl in elementary school… Wait, no.” Taiju shook his head, “He just wanted to meet her mom because she was a rocket scientist.”

“So we need a way to find out how Senku feels about us.”

“Great! But how do we figure that out?” Taiju asked.

“I don’t know…” Yuzuriha frowned.

Silence fell over the two of them as they tried to think of a way to solve their problem. Taiju nodded absently to himself while Yuzuriha chewed her lip, running her hands against her skirt.

After several quiet and intense moments of thinking, Yuzuriha suggested hesitantly, “Maybe we could individually tell him how we feel about the other? Like, you can tell him that you like me and then see how he responds and then I could tell him I like you. And then like, he’d admit to feelings because he’d be worried about interfering? And then we could be like, ‘no, no, it’s cool.’”

“Yeah, Yeah!” Taiju enthused, “I think I get it! But what if he only has feelings for one of us?”

“Oh, I hadn’t thought of that.” Yuzuriha tilted her head to the side, “Umm, well. I think I’d be okay if say, you dated both me and Senku, but me and Senku weren’t dating. After all, we’d still hang out with the three of us right? What about you?”

Taiju nodded seriously, “Yeah, I’d be fine if it was the opposite.”

Yuzuriha smiled, “Alright! So now we have to figure out; who should talk to him first?”

“Oh! I should go!” Taiju said with determination, “Senku would definitely have feelings for you, you’re the cutest person ever and your handiness with crafts is amazing!”

Yuzuriha waved her hands in front of her in denial as she blushed, “No no no! If he has feelings for anyone it’s you! You’ve known him for a long time and are always a rock of support when we need it!”

“Nuh-uh, it’s you!”

“No it’s you!”

“You!”

“No you!”

“Rock, paper, scissors?!” Taiju suggested.

“Alright, you’re on!”

With determination as if their lives were on the line, Yuzuriha and Taiju took ready stances that looked like they were about to fight and pumped their fists up and down dramatically together. On the final beat they threw out… rock.

They both threw out rock.

“Again!” Taiju shouted.

A rock-paper-scissors later and they both threw out rock again. 

And again.

And again.

“Okay, this time no rock!” Yuzuriha declared.

They both threw out scissors.

“You know what?” Yuzuriha said staring with furrowed brows at their matching hands, “I think I have a pair of cheap chopsticks in my backpack, I’ll break one in half and whoever draws the short stick has to confess.”

“Sounds good.” Taiju responded, staring equally confused at their hands.

After one draw later, it was determined that Taiju would talk to Senku first.

…

“Aw man.” Taiju sighed, falling back into the carpet of the living room in Senku’s family apartment, “You beat me again.”

Senku laughed as he said, “It takes more than button mashing to win a fighting game, y’know. You gotta consider strategy and timing.”

“I know, I know,” Taiju said despondently, “I just get too excited and end up pushing the buttons randomly!”

“Then I guess you’re doomed to lose,” Senku said smugly, then his smile softened and he tapped Taiju’s forehead with the back of his hand, “So you big oaf, what do you want to do next?”

“Oh!” Taiju exclaimed excitedly, sitting up again with crossed legs, “How about Monster Hunter!? You’re about to deal with the dragon thing right?”

“Kushala Daora yeah.” Senku said, leaning back on his arm, “Though I still have some things I need to gather. But do you really enjoy watching only me play?”

Taiju nodded enthusiastically, “Oh yeah! It’s actually kind of relaxing in a way.”

“Alright then,” Senku said with a smile, leaning over to switch the games in the console, “Monster Hunter it is.”

As Senku played, Taiju watched happily, enjoying the time hanging out with his friend.

After a while, Taiju asked, “Hey Senku? Can I tell you something?”

Senku grunted an assent, eyes still focused on the TV screen.

“I…” Taiju hesitated, uncertain, before saying in a rush, “really like Yuzuriha, like,  _ like  _ her like her.”

Senku turned his head slightly to look at Taiju for a moment, a small grin on his face, then turned back to his game, “I figured you’d tell me that at some point.”

“Really?!” Taiju exclaimed, “You knew?”

“Of course I knew,” Senku said with a shrug, “Though it took me a while to figure out. I didn’t realize the reason that you started getting embarrassed around Yuzuriha a lot more was because of a crush until about a year ago.”

“If you know about my crush on Yuzuriha then do you know that I…” Taiju trailed off.

“Know about what?” Senku asked, eyes narrowing as he focused on the battle he was currently in.

“Never mind!” Taiju said, rubbing the back of his head nervously as a slight blush suffused his cheeks.

Senku shot Taiju a confused look, one eyebrow raised before returning his attention to the game, “Alright then.”

With Senku uninterested in pressing the issue, Taiju relaxed, letting his arm drop. “I did want to ask how you felt if Yuzuriha and I started dating though. I don’t want you to feel awkward or anything.”

Senku smiled, “That’s quite thoughtful of you. But nah, I’ll be fine. In fact, I fully support you in your feelings. I think you and Yuzuriha would be good for each other. So don’t mind little ol’ me. You have my blessing.”

Taiju’s smile was slightly melancholy as he said, “Thanks Senku.”

…

**Senku:** _Running to the hardware store for supplies, need anything?_

**Yuzuriha:** _ Yeah! Meet u there in an hour? _

**Senku:** _ Got it _

**Yuzuriha:** _ (＾ω＾) _

When Yuzuriha arrived at the hardware store Senku was already there. He was standing near the entrance, staring contemplatively at his phone while holding a hand at the back of his neck.

“Sorry to keep you waiting!” Yuzuriha called, as she got close enough to speak.

Senku looked up from his phone with a small smile, “Nah, I wasn’t here long. Just going over my list one more time.”

“Then if you’re ready, shall we go in?” Yuzuriha asked cheerily.

Senku agreed and the two of them headed into the store, each of them grabbing a basket as they did so. As had become their habit, the two of them began wandering between the goods for sale, as much seeing if anything caught their eye as hunting for what they needed.

“So what are you looking for?” Senku asked as they passed through a variety of plants.

“A cousin of mine bought a used handloom that broke and she ended up giving it to me,” Yuzuriha answered, “I thought I’d fix it up and try my hand at weaving.” They stopped for a moment as Yuzuriha picked up an adorable little succulent plant in a baby blue pot. She debated whether she really needed another plant in her room, before putting it back down. “What about you?

“I lost my five millimeter wrench.” Senku said, eyes idly browsing the wares as they moved on, “I spent half the day turning my room upside down looking for it before resigning myself to buying a new one. Thought I’d stock up on some other things too while I’m out.”

Yuzuriha let out a light snort of amusement, “You know as soon as you get home you’ll find it right away right?”

Senku shrugged, “The odds are against it but,” he sighed, “that certainly feels like how it always goes doesn’t it?”

The two of them continued chatting idly as they filled their baskets with items that were on their lists. In the middle of one of the aisles, Yuzuriha asked, “Hey Senku?”

“Yeah?” Senku responded, digging around on the bargain shelf.

Swinging her basket slightly, Yuzuriha asked slowly, “How would you feel if Taiju and I started dating?”

Senku pulled his hands back, not finding anything interesting, and looked at Yuzuriha, an amused smile on his lips, “Did the big oaf finally ask you out?”

“Kinda…”

With a frown, Senku asked, “Is there a problem?”

“N-no” Yuzuriha shook head, looking down at her basket, “It’s just-” she peeked up at Senku from under her eyelashes, “That’s not going to make you jealous is it?”

Senku snorted, “Jealous that my two best friends are finally together after years of pining? Honestly I’ll be happy to not have that tension over my head when working on projects with you two.”

Yuzuriha nodded slowly, “Right.”

“Besides you know my biggest love will always be science.”

With a smile Yuzuriha looked up at Senku, “Of course! Just… let us know if your feelings change alright?”

“And have Taiju smother me as he demands to know what’s wrong?” Senku pulled an overdramatic disgusted face, letting his mouth curve downward as far as it could go, “No thanks.”

“Senku.” Yuzuriha said sternly.

“I’m kidding,” Senku said, raising a hand in surrender, “You know I trust you and Taiju with everything.”

“Good.” Said Yuzuriha with a smile, and bumped shoulders with Senku, “I’m glad.”

“Now enough mushy talk, let’s say we go pay?”

...

When chemistry club was over, Senku stepped out into the hallway to find Taiju and Yuzuriha waiting for him. The sight of them made his breath catch.

The two of them hadn’t noticed him yet, too absorbed in each other. Taiju had leaned down to peck Yuzuriha's cheek, a blush blooming over both their cheeks as they stared at each other with the softest expressions Senku had ever seen. It made his heart  _ ache _ but he couldn't fathom the reason why.

Yuzuriha noticed him first, turning her head to see him, and with a ten million watt smile, she waved. This caught Taiju’s attention and he looked at Senku, radiating happiness as he called out, “Senku! How was club!?”

It was enough to startle Senku out of whatever had come over him and he responded normally even as his chest still felt weirdly hollow, “Same as it always is. Though this time an argument broke out about what demonstrations we should show for the elementary schoolers in a month.”

“What did they decide?” Yuzuriha asked.

“Heck if I know.” Senku shrugged, “I mostly let the Prez and VP figure it out.”

As they headed out, continuing their after school chatter, Senku couldn’t help but wonder what his feeling was and whether he would experience it again.

As it turned out, he did. It happened again, and again, leaving a tight squeezing feeling in his chest. Senku kept track of when the instances happened in his mind, trying to unravel whatever emotion was behind it. Most of the time it appeared whenever Yuzuriha and Taiju were being cutesy with each other; when Taiju pulled Yuzuriha close to keep her from being run over by a bike and continued to hold her near as they kept walking, or the way Yuzuriha’s hands would linger fondly as she straightened out Taiju’s school uniform.

Senku thought maybe it was envy, but that didn’t seem quite right. What was he even envious of? Not to mention he would occasionally get the ache-y feeling when just alone with one of them. Like when Senku had shown off his latest finished project to Taiju and the boy enthused praise over how well it worked. Or when he had been helping Yuzuriha study, Taiju busy with his part-time job, and Senku had conceded to letting Yuzuriha braid his hair during a break. There was something… more? That he wanted. He just couldn’t put his finger on what, no matter how many times the feeling appeared. And there was nothing more frustrating than receiving consistent results from an experiment and having no idea how to interpret them.

Then there was a breakthrough. Senku had a fleeting thought of Taiju’s warm steady hands on his shoulders as he leaned down for a kiss. Immediately a flush suffused Senku’s cheeks as he thought ‘ _ Oh.’ _

Senku had to stop the videogame he was playing at that point, retreating to his bedroom to collapse backwards onto his bed in shame.  _ He was an idiot. _ How did he not pick up that he had a crush on Taiju? Probably because a crush slotted in so easily with all the other affection he felt for the big oaf.

However, Senku was a scientist and nothing but thorough. So just in case, he pictured Yuzuriha, her hands on each side of his face while she held him where she wanted him. A playful smile was on her lips before she leaned up and… Yep. Senku definitely felt something for Yuzuriha too.

Throwing an arm over his eyes, Senku repeated this process, trying to picture kissing several other acquaintances around his age, but each time he felt a sliver of disgust. Which confirmed it. Senku had, well, ‘feelings’ for his two best friends. His two best friends who were already dating. Each other.

Senku groaned. This is why he liked science. Science was never as messy as  _ feelings. _

But complaining about it wasn’t going to solve anything. He needed to do something, but what? Well, he had gotten this far watching Yuzuriha and Taiju date without anything terrible happening. Maybe he could just, keep it to himself? It seemed a little late to say anything now. But wasn’t late better than never? Besides what was he afraid of if he did tell them? That they’d reject him? Yeah that might hurt, but he knew they’d still be friends afterward. And honestly he’d rather have that out in the air and move on than have it all bottled up with nowhere to go.

So, Senku decided. He’d just have to confess.

Except, Senku realized a day later as the three of them ended up at Yuzuriha’s apartment after school, he didn’t know how one went about confessing. In the movies it was all about grand gestures and proving one’s love. Senku could see Yuzuriha enjoying that kind of thing, heck, Taiju would probably get excited over it too. But the dramatics and flair was always pointless to him. If you loved someone, they shouldn’t need all that extra stuff to know you meant it.

And Taiju and Yuzuriha had been his friends for years, they’d understand him.

So as they sat on the small apartment balcony table drinking lemonade, Senku mustered up his courage and said, “Uh, guys? I have something to say.”

“Hmm? What is it Senku?” Yuzuriha asked as both she and Taiju stopped playfully flicking lemonade at each other with their straws, as if they sensed that Senku was about to say something serious.

“It’s uh-” Suddenly it felt like Senku’s mouth had dried up, the lack of moisture making it impossible to speak.

“Take your time!” Taiju encouraged with a smile, seeing Senku’s hesitance.

Senku nodded, and took a sip of his lemonade to wet his throat. Then he said bluntly, “I like you, both of you.”

The two of them stared at him blankly, eyes blinking owlishly. A few seconds went by without a response.

“As more than friends.” Senku added exasperatedly.

Taiju and Yuzuriha continued to stare owlishly, but this time they glanced at each other, staring for a moment.

“We like you too!” The two of them exclaimed at the same time, their bright excited faces turning to look at Senku.

This time it was Senku’s turn to blink owlishly, “You do?”

“Of course!” Taiju replied, “How could we not? You’re always there for us and teach us so many cool things! Even if we don’t understand it all the time.”

“So if you’d like,” Yuzuriha offered her hand, palm up on the table, “Would you want to date us?”

Senku stared at Yuzuriha’s hand, somehow shocked to see them so willing to have him join in the romance they had constructed. But as Taiju reflected Yuzuriha’s gesture, Senku found it the easiest thing in the world to place his hands in theirs and hold them tight. “I would love to.”

Yuzuriha nodded, “Then it’s settled.”

And as Taiju and Yuzuriha began their splish fight again, Senku joined in, grabbing the straw with his mouth so he could continue to hold onto his girlfriend and boyfriend’s hands.

**Author's Note:**

> I have a [tumblr](https://legendaryandroid.tumblr.com/)! Feel free to chat, or something?


End file.
